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Knife Shapening

Started by rmisale, October 21, 2015, 02:31:17 AM

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rmisale

I am on an iPhone so can't attach a picture.

grepper

Is the knife very thin, i.e., from the spine to the cutting edge?  Is it possible that the jig is impacting the grinding wheel?  This is possible on thin knives.

Does either side of the jig show wear from impacting the wheel?

What bevel angle are you trying to sharpen to?

The only way you could get an uneven bevel is if the blade is not centered in the jig or possibly the jig is hitting the wheel when it is flipped.

Clamp the jig as close to the spine as possible. 

You probably don't need the long knife jig for a 6" knife.  Have you tried the regular jig?

rmisale

It's not super thin.
I don't think the jig is touching the wheel and I am trying to sharpen to 25 degrees.
I will try the smaller jig and the poisoning.

Thank you for your help

grepper

If you use the Angelmaster does is show the same angle on each side of the knife?  If not, can you tell why?

I suppose that it's possible that somehow you have ground an unequal bevel in which case you could just grind until it's even again.

Double check to be sure that the jig is not touching the wheel on either side. 

It's odd that you are seeing this on more than one knife.

Glad to try and help. :)  We'll get to the bottom of what's going on.  Simple knife sharpening should not be difficult.

wootz

Quote from: rmisale on October 23, 2015, 01:47:10 AM
Hi
Another question.

It seems that the bevel on one side of the knife is different than the other side.
I do the first side then flip the knife and do the other side.
One is wider than the other?
Just wondering if this could be part of the problem?

Uneven bevels result from the design of the knife jigs, and is more noticeable with the long knife jig. The thicker the knife, the more the difference.
It was discussed in the Long Knife Jig asymmetry problem topic http://forum.tormek.com/index.php?topic=2577.0


wootz

As to honing, let me quote Jeff Farris:

Edge rounded by honing
This one happens seldom enough to almost qualify as an urban myth.  There's a lot more theoretical rounding over going on in various bulletin boards than real life rounding over happening on TORMEK machines.  You have to bring the angle way, way too high to actually start rounding over an edge.  That said, when you begin using the system, it may not be that easy to tell where you are on the wheel with relation to the edge. One way to solve the rounding issue is to use the jig when honing the bevel.  With the jig, you can apply much more pressure to the honing wheel, thus speeding up the job and preventing round over.
... work at 3 o'clock on the honing wheel, instead of 11 or 12. Now, you can look straight down at the gap between the edge of the tool and the leather.  Start out with your angle too low, and then slowly bring the angle up until the edge just barely touches the leather.  Now, you'll polish the surface and remove the burr without creating a back bevel or rounding the edge.

grepper

If we are still talking about the 6" fillet knife, I suspect the blade is not that thick.

Have you tried the regular knife jig?

Have you managed to get it sharp?  (The question that started this thread.)

Jan

#22
Quote from: rmisale on October 23, 2015, 01:47:10 AM

It seems that the bevel on one side of the knife is different than the other side.
I do the first side then flip the knife and do the other side.
One is wider than the other?
Just wondering if this could be part of the problem?

Raloh, the cause of your problem could be following: if your knife has a tapered blade and the knife jig grips only some 2 mm (5/64") of the blade, than the position of the knife in the jig may be instable. Is it because, the jig clamps are in contact mostly with the widest part of the blade, along the spine. In the state of rest the blade is centered, but under the pressure of fingers during sharpening, it can easily be skewed.

Jan

rmisale

Again so amazing the support from everyone.

Thank you!!

You have all given me a lot to work with. 
I will let you know how I make out.


Thanks again.

wootz

#24
And don't assume that the stone wheel out of the box is true - it is not. And it is next to impossible to get a shaving edge on a wheel that is out of true. I've unpacked the 3rd stone by now, none of them was true nor perfectly round out of the box.

My first knives on Tormek were as disappointing as yours.
I remember doing these simple things gave me the first shaving edge:


  • Use regular knife jig (forget the long jig for now).
  • True the stone.
    Don't grade it yet - grind the bevel at the set angle on the freshly trued surface.
  • Then grade the stone fine (#1000), and grade hard.
  • Do as many passes as needed to get burr on one side.
  • Inspect the edge, and continue on the same side till you smooth away all scratches left by course beveling, and get even finish along the whole length of the edge.
  • Then flip over, and get the burr on the other, and get even finish.
  • Flip over to the initial side, and do one more light pass.
  • Remove the jig, and hone freehand as  Jeff Farris taught:
Hold the side of the blade, edge up, at 3 o'clock on the honing wheel (instead of 12), about half an inch from the edge. Stand just above and stare straight down into the gap between the edge and the leather wheel. Bring the edge to the leather slowly until the exact point where the gap disappears, until the edge just barely touches the leather. STOP!
Make slow pass across the wheel.
Turn around to hone another side of the blade (now at 9-10 o'clock), and do the same.
Overall do 4 alternating passes across the leather wheel.

At this point the blade will shave your forearm.

Knives should be mounted in the jig as shown by Jan. This helps avoid jig position effect on the bevel described in the Tormek Handbook p.53.



Elden

#25
Quote from: wootz on October 23, 2015, 10:56:24 PM
Stand just above and stare straight down into the gap between the edge and the leather wheel. Bring the edge to the leather slowly until the exact point where the gap disappears, until the edge just barely touches the leather. STOP!

Vadim,
   Good explanation. I trust you are doing this on the back side of the honing wheels so that the direction of the leather hone travel is upward instead of downward (in other words, away from the knife edge).  For someone new, it might be taken to do it with the hone turning into the knife edge. There are several reports in the archives of cut or ruined leather hones from that approach.
Elden

wootz

#26
You're damn right, Elden!
Following you remark, I tried editing my post to make this clear, but probably it reads even more confusing now.  :-\
Honing must always be carried out away from the edge.

rmisale

You guys are great. 

Thanks again.

Have a question from a friend.
Would the t4 be okay for home use? Mostly for knives.



grepper

We'll let Ken answer that question. :)

I have a question:  Have you gotten a sharp edge yet?

rmisale

Getting there but I am sure I can get better.
Only have been trying for a week.